1. Field of Invention
The present invention relates to a scanner carrier. More particularly, the present invention relates to a carrier structure inside the scanning module of a contact image sensor (CIS) type optical scanner.
2. Description of Related Art
Contact image sensor (CIS) is a type of linear scanner commonly used for scanning an image or a document. The image or document is captured in an electronic format for ease of storage, display, processing and transmission. Due to a modular design, the CIS is easy to assemble, light, compact and costs less to produce.
FIG. 1a is a front view of the scanning module of a conventional contact image sensor and FIG. 1b is a cross-sectional view of the scanning module. As shown in FIGS. 1a and 1b, a conventional contact image sensor (CIS) 100 consists of a linear light source 104, a self-focus lens array 101 and a sensing array 102 over a substrate board 103. The light source 104, the self-focus lens array 101, the sensing array and the substrate board 103 are mounted on an aluminum frame 105. In a scanning operation, the self-focus lens array 101 reflects light coming from the original document and forms an image on the sensing array 102. The sensing array 102 converts a line of color or gray scale light into electronic signals. Throughout the scanning session, the scanning surface 110 of the scanning module 100 in constant contact with a document platform 200 via a buffer plate 300 is pulled forward or backward by an electric motor.
The convention CIS scanning module 100 uses the buffer plate 300 for close contact between the scanning surface 110 and the document platform 200. In general, an external locking mechanism or supporting element is present to ensure a close contact between the scanning module 100 and the document platform 200 during scanning movement. However, the locking mechanism or supporting element is a mechanical prop that only provides support in a few fixed locations on the scanning module 100. Hence, close contact everywhere with the document platform cannot be ensured.